There’s a New Bug in Town

The discovery of a new, never-before reported pest insect can create quite a stir. That happened last week right here in my hometown of West Lafayette, Ind. Yes, indeed, in our fair city on the banks of Indiana’s most famous river, the Wabash, a brown marmorated stink bug showed up.

Brown marmorated stink bug

Actually quite a few of these stink bugs were probably living here this year, and maybe even for the last year or two, but no one had really noticed. You see this stink bug looks a lot like all the other stink bugs that crawl around in our gardens and lawns. But even though it might look similar to other stink bugs ,this one is a different species.

This particular species of stink bug is called an exotic species. That means the insect isn’t native to North America. That also means it is likely to cause problems right here in River City -- and anywhere else it gets established, for that matter. That is because in its native range of China, Japan, Korea and Taiwan it is a pest of fruits, vegetables and farm crops.

Of course, this is not the first exotic pest insect to find its way to the United States. There have been literally dozens of insect species that have hitchhiked to these shores. The list includes some of our most damaging insect pests, including the European corn borer, the Japanese beetle, the Hessian fly, several species of mosquitoes and the emerald ash borer. All were stowaways associated with international commerce.

Most likely, the brown marmorated stink bug arrived from Asia as a stowaway in packing crates. It was first documented from near Allentown, Pa., in 1998. Since that time, the insect has been found in many other U.S. locations, including most eastern states and in Oregon.

So how did this new bug get to our town? It probably was the result of a natural population spread westward. This insect, like all insects, is prone to expand its range into unoccupied territory. In much the same fashion, European settlers moved westward in the early days of our country following the establishment of settlements on the eastern seaboard.

Stinkbugs, as their name suggests, are capable of producing an odor. This is a defense mechanism, and the odor is from a chemical released through holes in the abdomen. Generally, the chemical is emitted when the insect is physically abused in some way. This particular stink bug is about ¾ inch long as an adult and is called marmorated because its general brown color is laced with streaks of white in a marble-like pattern. You can distinguish it from similar bugs by the white band on the antennae or alternate black and white bands on the portion of the abdomen that shows at the edges of the wings.

So what are we to expect from this new bug in town? First, it will begin to cause some problems for fruit and vegetable growers. Like all stink bugs, this insect feeds by using its piercing/sucking type mouthparts to extract sap from plants. It will not only suck sap from stems and leaves but also from many fruits, including peaches, apples, tomatoes, beans and sweet corn. Such feeding results in deformed growth of the fruit that is known as cat facing.

Another potential problem is that stink bugs overwinter as adults. Like other insects that spend the winter as adults, stink bugs try to find protected places for the cold season. That means the search for a wintering site could result in home invasions. Unfortunately, the brown marmorated stink bug is more prone to coming inside human habitations than other stink bugs.

All told, this new stink bug is not going to be appreciated by the human population of our fine city. After all, it makes an odor, damages fruits and vegetables and invades our homes. In baseball, three strikes mean you’re out. Unfortunately, this exotic insect pest doesn’t adhere to baseball rules. So the brown marmorated stink bug is here to stay and make us wish it hadn’t ever found its way here, just like all of those other accidental insect introductions of the past 200 or so years.